/Engine/Source/Runtime/SlateCore/Public/Animation/CurveSequence.h
Add a new curve relative to the current end of the sequence. Makes stacking easier. e.g. doing AddCurveRelative(0,5); AddCurveRelative(0,3); Is equivalent to AddCurve(0,5); AddCurve(5,3)
[FCurveHandle](API\Runtime\SlateCore\Animation\FCurveHandle) AddCurveRelative ( const float InOffset, const float InDurationSecond, const ECurveEaseFunction InEaseFunction )